1. Field of the Invention
The present invention is directed generally toward data storage and backup systems. More specifically, the present invention is directed toward a backup system that can create a number of mountable representations of past contents of storage volume.
2. Background of the Invention
A data replication system can provide an up-to the-minute duplicate copy or replica of changing data on a storage device. Write commands issued to a primary storage device are duplicated and issued to the data replication system, which records the written data in its own storage medium. The simplest form of data replication is a redundant “mirror” volume, which is itself a duplicate of the primary storage device. More sophisticated data replication systems store not only a current duplicate copy of the primary device but also allow additional past-time images or “point-in-time views” of the primary device to be accessed. This may be done through some kind of “journaling,” where the write commands themselves are archived, rather than simply a copy of the data.
These data replication systems are powerful because they may allow for a virtually limitless number of point-in-time views representing different points in time. When a data replication system is shared among a group of users working together, it may be useful for the group to be able to work with a one or more point-in-time views and ensure that all users are accessing the same point-in-time views. For example, a group of programmers working on a large program may wish to be able to access a particular version of the source code to that program that existed at a particular time. Thus, a need exists for a system to produce commonly accessible, consistent point-in-time views for use by a group of users.